MIMO ANTENNA SYSTEM

• US 20100119002A1
• Filed: 11/12/2008
• Published: 05/13/2010
• Est. Priority Date: 11/12/2008
• Status: Active Grant

• Current Assignee: Cambium Networks Limited (Cambium Networks Corporation)
• Original Assignee: Xirrus Incorporated
• Inventors: Hartenstein, Abraham
• Granted Patent: US 8,482,478 B2
• Time in Patent Office: Days
• US Class Current: 375/267
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001

Abstract

A wireless local area network (“WLAN”) antenna array (“WLANAA”) includes a circular housing having a plurality of radial sectors and a plurality of primary antenna elements configured as Multiple-Input, Multiple-Output (MIMO) antennas. Each primary antenna element, which includes multiple antennas connected to a single radio, being positioned within a radial sector of the plurality of radial sectors.

Claims

1. A wireless local area network (“

WLAN”

) antenna array (“

WLANAA”

) comprising;

a circular housing having a plurality of radial sectors; and

at least one radio in each radial sector, the at least one radio coupled to send and receive wireless communications via a plurality of antenna elements configured as Multiple-Input, Multiple-Output (MIMO) antennas wherein each of the plurality of antenna elements are positioned within an individual radial sector of the plurality of radial sectors.

2. The WLANAA of claim 1 further including at least one absorber element between each radial sector.

3. The WLANAA of claim 2 further including a plurality of absorber elements where each absorber element of the plurality of the absorber elements is located between an adjacent pair of primary antenna elements.

4. The WLANN of claim 1 where the plurality of radios are coupled to MIMO antennas that are of:

a first type of MIMO antennas for communicating signals that conform to the IEEE 802.11bg standard;

or

a second type of MIMO antennas for communicating signals that conform to the IEEE 802.11a standard.

5. The WLANAA of claim 4 where the first type of MIMO antennas include three dual-monopole antennas substantially evenly spaced along a perimeter of the radial sector of the radio connected to the first type of MIMO antennas.

6. The WLANAA of claim 4 where the second type of MIMO antennas include two dual-polarized antennas configured at the +45°

and −

45°

polarizations and one two-element dipole antenna, orthogonal to the dual-polarized antennas.

7. The WLANAA of claim 6 where the two-element dipole antenna is embedded on a main RF printed circuit board (PCB) and the two dual-polarized antennas are printed on an antenna printed circuit board (antenna PCB) mounted substantially vertical relative to the main RF PCB.

9. The WLANAA of claim 4 where the second type of MIMO antennas include two linearly polarized antennas and one two-element dipole antenna orthogonal to the two linearly polarized antennas.

10. The WLANAA of claim 9 where the two-element dipole antenna is embedded on a main RF printed circuit board (PCB) and the two dual-polarized antennas are printed on an antenna printed circuit board (antenna PCB) mounted substantially vertical relative to the main RF PCB.

11. The WLANAA of claim 9 where the two linearly polarized antennas are two 1×

2 dipole element sub-arrays.

12. The WLANAA of claim 9 further comprising a reflector between the two 1×

2 dipole element sub-arrays.

13. The WLANAA of claim 1 where the at least one radio in each radial sector communicates over a first type of MIMO antennas for communicating signals that conform to the IEEE 802.11bg standard, the WLANAA further including:

a second plurality of radial sectors within the same circular housing, each of the second plurality of radial sectors including a second type of radio for communicating via a second plurality of antenna elements configured as second-type MIMO antennas for communicating signals that conform to the IEEE 802.11a standard.

8. The WLANAA of claim 8 where the two dual-polarized antennas are two element patch antenna sub-arrays configured at the +45°

and −

45°

polarizations.

14. An RF sub-system comprising:

an RF printed circuit board (“

PCB”

) having at least one radio;

a plurality of antenna PCBs mounted orthogonal to the RF PCB along an edge of the RF PCB, the antenna PCBs having a plurality of MIMO antennas connected to the at least one radio; and

a connector on the RF PCB for connecting the RF sub-system to a central PCB, the central PCB having connectors along its perimeter for connecting a plurality of RF PCBs such that the MIMO antennas provide 360 degrees of coverage when all available connectors are connected to corresponding RF PCBs.

15. The RF sub-system of claim 14 where the at least one radio includes at least one radio of a first type, the RF sub-system further comprising:

a radio of a second type connected to M MIMO antennas.

16. The RF sub-system of claim 15 having M antenna PCBs where:

each of the M antenna PCBs includes one antenna for the radio of the second type; and

where the at least one radio of the first type is connected to N MIMO antennas, where at least some of the N MIMO antennas are on one of the antenna PCBs and the rest are on the RF PCB.

17. The RF sub-system of claim 16 where:

the antenna PCBs include PCBs from a group consisting of;

a first-type antenna PCB having antenna elements for the radio of the first type,

a second-type antenna PCB having antenna elements for the radio of the first type,

a dual-type antenna PCB having antenna elements for the radio of the first type and the radio of the second type,

and any combination thereof.

18. The RF sub-system of claim 16 where:

the second-type antenna PCB includes dual-monopole antennas.

19. The RF sub-system of claim 17 where:

the first-type antenna PCB includes dual-polarized antennas configured at +45 and −

45 polarizations.

20. The RF sub-system of claim 19 where:

the dual-polarized antennas include a two-element patch antenna sub-array excited by two orthogonal feed networks.

21. The RF sub-system of claim 19 where:

the RF PCB includes at least one first-type antenna orthogonal to the dual polarized antennas to provide polarization diversity.

22. The RF sub-system of claim 17 where:

the first-type antenna PCB includes at least one 1×

2 dipole sub-array.

23. The RF sub-system of claim 17 where:

the first-type antenna PCB includes two linearly polarized 1×

2 dipole sub-arrays and a reflector.

24. The RF sub-system of claim 23 where:

the RF PCB includes at least one first-type antenna orthogonal to the dual polarized antennas to provide polarization diversity.